<!DOCTYPE html>
<html>

    <head>
        <meta charset="UTF-8">
        <script>
            function boom()
            {
                document.documentElement.offsetHeight;
                document.body.appendChild(document.getElementById("x"));
                document.documentElement.offsetHeight;
            }
        </script>
    </head>

    <body style="-moz-column-count: 4;" onload="boom();">
        <div style="float: left; height: 10px; width: 10px;">
            <div id="x">
                <div style="height: 80px;"></div>
                <div style="float: left; height: 10px;"></div>
            </div>
        </div>
    </body>

</html>
